The commune is mainly known as the location of a research unit of INRIA (in the Domaine de Voluceau, formerly Camp Voluceau, used by SHAPE) as well as a freeway exchange known as the Rocquencourt Triangle (triangle de Rocquencourt), which is often mentioned in traffic news.

While negotiating the final armistice, Exelmans was ordered to attack the Prussians at Versailles on 1 July 1815. Under attack the Prussians retreated from Versailles and headed east, but were blocked by the French at Vélizy. They failed to re-enter Versailles and headed for Saint-Germain-en-Laye. Their first squadron came under fire at the entrance of Rocquencourt and attempted to escape through the fields. They were forced into a small, narrow street in Le Chesnay and killed or captured. However, the main body of the Prussian army succeeded in reaching Saint-Germain. (From Presentation of Rocquencourt.)